PS-1230 PS-1152 Fix/improve null origin message (#3280)

* Improve message if Origin header value is empty

* PS-1230 Remove serve feature flag

apps/cli/src/flags.ts

@@ -1,5 +1,5 @@
-export type Flags = {
-  serve?: boolean;
-};
+// Remove this linter hint if any flags exist
+// eslint-disable-next-line @typescript-eslint/ban-types
+export type Flags = {};
 
 export type FlagName = keyof Flags;